Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Host-seeking behaviour of Anopheles mosquitoes in response to olfactory and visual cue

Abstract: Chapter 18 IntroductionSuccess in malaria vector control in recent years has been attributed largely to the widespread distribution and utilization of long lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS)(WHO, 2019). The disruption of contact between the human host and the vector remains a very effective mechanism of controlling mosquito-borne diseases when applied in combination with other tools such as effective diagnosis, prevention of mother to child ...

Understanding Striga occurrence and risk under changing climatic conditions across different agroecological farming systems at local and regional scales

Abstract: The invasion by Striga in most cereal crop fields in Africa has posed an acute threat to food security and socioeconomic integrity. Consequently, numerous technological and research developments have been made to minimize and even control the Striga impacts on crop production. So far, efforts to control Striga have primarily focused on the manipulation of the genetics of the host crops, as well as understanding the phenological and physiological traits, along with the chemical comp...

Chemical ecology of plant-to-plant communication and opportunities for maize stemborer management in Africa

Abstract: Maize is the most widely grown cereal crop worldwide, and is the most important staple crop in sub-Sahara Africa. The spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera:Crambidae) is considered among the most important pests of maize and the damage it causes may result in yield losses of up to 88%. Previous studies showed that plants damaged by herbivores release huge amounts of volatile compounds, known as herbivore-induced plant volatiles (HIPVs) into the environment, whic...

Damage to citrus and vegetables by Thaumatotibia leucotreta (Lepidoptera: Tortricidae) and prospects for control with entomopathogenic fungi

Abstract: Globally, orange is one of the major fruit crops contributing to nutrition and monetary income. False codling moth (FCM), Thaumatotibia leucotreta, is one of the major constraints of orange production. Before this study, little was known regarding the bioecology of FCM in orange and vegetables in Kenya and Tanzania and the potential use of dry conidia of entomopathogenic fungi for control of T. leucotreta moths has not been tested. There is also no IPM strategy available for FCM in...

Assessment of the diversity and roles of bacterial symbionts in fruit fly development and response to biological control

Abstract: Tephritid fruit flies are among the most destructive pest species of fruits and vegetables in many regions of the world. Apart from high losses in yield, tephritid fruit fly pests pose great socioeconomic and ecological challenges as well as demand effective measures to curb infestation which can be costly. Among currently used management options are the use of chemical insecticides, behavioral, genetic, cultural and biological approaches. However, no single method or combination o...

Effects of variation in plant quality on densities and sizes of herbivores, primary and secondary parasitoids

Abstract: To investigate the effects of variation in host quality on densities and sizes of three levels of consumers, a cabbage-aphid-parasitoid foodweb was analyzed. Three close related cabbage populations were studied: Brassica oleracea var. gemnifera cv. Cyrus, a feral Brassica oleracea and a wild cabbage type Old Harry as source of variation in host plant quality. A field experiment were established in Wageningen, The Netherlands to measure the effects on densities of herbivores. Aphids...

The Spatial Distribution of Mosquitoes Related To the Environment on Rusinga Island, Western Kenya

Abstract: The SolarMal project on Rusinga Island, Western Kenya, aims to eliminate malaria by reducing the mosquito population, using a new developed mosquito trap which will be installed at all households on the island. The effect of the installed traps is monitored by sampling mosquitoes from randomly selected selected households on the island during the whole duration of the project. This thesis project aims to support the SolarMal project by performing spatial analysis to the distributio...

Determination of Neonicotinoid Residues in Hive Products from Kiambu and Nairobi Counties, Kenya

Abstract: Information on pesticide residue occurrence in hive products is scanty or lacking yet it is important so as to safeguard human health from effects of pesticides. The aim of the study was to identify and quantify neonicotinoid residues in hive products. The study was undertaken for 6 months between (March-August, 2015) at Kiambu and Nairobi Counties. The objectives of the study were to find out the pesticides used in the cultivation of crops, the frequency of use and the concentrati...

Crop diversification using improved sweet potato [Ipomoea batatas (L.) Lam.] varieties as an adaptation strategy to climate varibility by subsistence farmers in Taita Hills, Kenya

Abstract: A study on mechanisms used by subsistence farmers to cope with climate variability and change was conducted in the Taita Hills, Kenya from January 2014 to March 2015. Household surveys together with key informant interviews were used to collect data to assess farmers’ use of crop diversification as a strategy to cope with climate variability and change. Further there was an assessment of past crop records in relation to weather and climate data in the area. The study then assesse...

Development of Efficient Tools for Improved Surveillance of Vectors of Dengue and Chikungunya Fever.

Abstract: In the past 3 decades, arboviruses have become a major cause of re-emerging epidemic diseases in the world. Amongst the arboviruses, dengue and chikungunya fevers which are transmitted by Aedes spp have become more prevalent and have spread far beyond traditional areas of distribution - mainly in Africa and Asia - to cause severe morbidity, mortality, and economic harm. Currently control of these diseases solely depends on vector control as there is no treatment or vaccine. This ca...

Optimising a Resting box to enhance Adult Gravid Female Mosquitoe Auto-disseminate Larvicide in a Semi field

Abstract: Malaria control strategies that target adult mosquitoes are challenged by the emergence of insecticide resistance and behavioral changes of vectors. The conventional approach of applying larvicides is limited by high operational costs and inadequate knowledge of mosquito breeding habitats especially in rural African communities. This study developed a potential mosquito contamination site, assessed the potential of adult female Anopheles gambiae s.s to pick up fluorescent dye and a...

Assessment of information flow and ex-ante impact of potential cashew integrated pest’s management strategies for sustainable cashew production: the case of Tandahimba and Lindi rural distric

Abstract: This study was conducted to assess information flow and ex-ante impact of potential cashew IPM strategies for sustainable cashew production and marketing in Tanzania. Radio, extension workers, leaflets, posters, cashew development centres, on farm demonstrations and television were the identified information sources and communication pathways. Farm profit analysis of Potential IPM options were also quantified to find out the economic feasibility of cashew production at individual f...

Assessment of the Potential for Integration of Ecosystem Based Approaches and Local Indigenous Knowledge into Climate Change Adaptation in the Taita Hills, Kenya

Abstract: The integration of indigenous knowledge and science through and ecosystem based adaptation provides a basis for the formulation of culturally acceptable and sustainable adaptation practices. This study aims to determine sustainable climate change adaptation strategies for the Taita Hills in Kenya and assess their potential for integration with ecosystem based adaptation. It uses a mixed methodology that involves literature review, participatory methods and household surveys. As a r...

Assessment Of Conservation Agriculture As An Adaptation Option To Climate Change In The Taita Hills, Kenya

Abstract: Climate Change and Variability affects water supply and food security, especially in developing countries where many small-scale farmers rely on rain-fed agriculture for food production and as a main source of livelihood. The extent of the effects of climate change and variability on these small-scale producers largely depends on their level of adaptation, adaptive capacity, exposure and vulnerability. This study evaluates the effectiveness of Conservation Agriculture (CA) as a pos...


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